Azalea plant named ‘RLH1-4P19’

ABSTRACT

A new and distinct cultivar of  Azalea  plant named ‘RLH1-4P19’, characterized by its compact, upright, outwardly spreading and globose plant habit; freely branching habit; dense, bushy and vigorous growth habit; evergreen and persistent dark green-colored leaves that do not abscise during the winter; freely flowering habit during spring and from summer until frost in autumn; large purple-colored flowers that are not persistent; single star-shaped flower form; and excellent garden performance.

Botanical designation: Rhododendron hybrida.

Cultivar denomination: ‘RLH1-4P19’.

BACKGROUND OF THE INVENTION

The present Invention relates to a new and distinct cultivar of Azalea plant, botanically known as Rhododendron hybrida, an evergreen Azalea, and hereinafter referred to by the name ‘RLH1-4P19’.

The new Azalea plant is a product of a planned breeding program conducted by the Inventors in Long Creek, Oconee County, S.C. The objective of the breeding program is to create new compact evergreen Azalea plants having dense growth habit, large attractive flowers, good foliage retention during the winter, consistent summer reblooming qualities and cold hardiness.

The new Azalea plant originated from a cross-pollination made by the Inventors in 1996, Long Creek, Oconee County, S.C., of a proprietary selection of Rhododendron hybrida identified as code number RLH-1900-RP, not patented, as the female, or seed, parent with a proprietary selection of Rhododendron hybrida identified as code number RLH-19-PAF, not patented, as the male, or pollen, parent. The new Azalea plant was discovered and selected by the Inventors as a single flowering plant within the progeny of the stated cross-pollination in a controlled greenhouse environment in Long Creek, Oconee County, S.C. in 2000.

Asexual reproduction of the new Azalea plant by semi-hardwood stem cuttings in a controlled greenhouse environment in Long Creek, Oconee County, S.C. since 2005, has shown that the unique features of this new Azalea plant are stable and reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

Plants of the new Azalea have not been observed under all possible environmental conditions. The phenotype may vary somewhat with variations in environment such as temperature and light intensity without, however, any variance in genotype. The following traits have been repeatedly observed and are determined to be the unique characteristics of ‘RLH1-4P19’. These characteristics in combination distinguish ‘RLH1-4P19’ as a new and distinct Azalea cultivar:

-   -   1. Compact, upright, outwardly spreading and globose plant         habit.     -   2. Freely branching habit; dense, bushy and vigorous growth         habit.     -   3. Evergreen and persistent dark green-colored leaves that do         not abscise during the winter.     -   4. Freely flowering habit during spring and from summer until         frost in autumn.     -   5. Large purple-colored flowers that are not persistent.     -   6. Single star-shaped flower form.     -   7. Excellent garden performance.

Plants of the new Azalea differ from plants of the female parent selection in the following characteristics:

-   -   1. Plants of the new Azalea are more freely branching than         plants of the female parent selection.     -   2. Plants of the new Azalea are more freely flowering than         plants of the female parent selection.     -   3. Plants of the new Azalea have larger flowers than plants of         the female parent selection.     -   4. Plants of the new Azalea have single flowers whereas plants         of the female parent selection have semi-double flowers.     -   5. Flowers of plants of the new Azalea are purple in color         whereas flowers of plants of the female parent selection are         pink in color.

Plants of the new Azalea differ from plants of the male parent selection in the following characteristics:

-   -   1. Plants of the new Azalea are more upright and more freely         branching than plants of the male parent selection.     -   2. Plants of the new Azalea have darker purple-colored flowers         than plants of the male parent selection.

Plants of the new Azalea can be compared to the plants of ‘Robleg’, disclosed in U.S. Plant Pat. No. 15,227. In side-by-side comparisons conducted in Long Creek, Oconee County, S.C., plants of the new Azalea differed from plants of ‘Robleg’ in the following characteristics:

-   -   1. Plants of the new Azalea were more freely branching than         plants of ‘Robleg’.     -   2. Plants of the new Azalea were more freely flowering than         plants of ‘Robleg’.     -   3. Flowers of plants of the new Azalea were purple in color         whereas flowers of plants of ‘Robleg’ were white in color.     -   4. Plants of the new Azalea flowered during the spring, summer         and autumn whereas plants of ‘Robleg’ flowered only in the         spring and autumn.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the overall appearance of the new Azalea plant. These photographs show the colors as true as it is reasonably possible to obtain in colored reproductions of this type. Colors in the photographs may differ slightly from the color values cited in the detailed botanical description, which accurately describe the colors of the new Azalea plant.

The photograph on the first sheet comprises a side perspective view of a typical flowering plant of ‘RLH1-4P19’ grown in a container.

The photograph on the second sheet is a close-up view of a typical flower of ‘RLH1-4P19’.

DETAILED BOTANICAL DESCRIPTION

The aforementioned photographs and following observations and measurements describe plants grown in Long Creek, Oconee County, S.C. in 5.7-liter containers, in a polypropylene-covered shade house during the late summer and under commercial production conditions. During the production of the plants, day temperatures ranged from −5° C. to 40° C. and night temperatures ranged from −25° C. to 35° C. Plants used for the photographs were five years old and plants used for the description were two years old. In the following description, color references are made to The Royal Horticultural Society Colour Chart, 2007 Edition, except where general terms of ordinary dictionary significance are used.

-   Botanical classification: Rhododendron hybrida ‘RLH1-4P19’. -   Commercial classification: Evergreen-type Azalea. -   Parentage:     -   -   Female, or seed, parent.—Proprietary selection of             Rhododendron hybrida identified as code number RLH-1900-RP,             not patented.         -   Male, or pollen, parent.—Proprietary selection of             Rhododendron hybrida identified as code number RLH-19-PAF,             not patented. -   Propagation:     -   -   Type.—By semi-hardwood stem cuttings.         -   Time to initiate roots, summer.—About 25 to 30 days at             temperatures of 27° C. to 30° C.         -   Time to initiate roots, winter.—About 35 to 45 days at             temperatures of 16° C. to 17° C.         -   Time to produce a rooted young plant, summer.—About 60 to 70             days at temperatures of 27° C. to 30° C.         -   Time to produce a rooted young plant, winter.—About 80 to             100 days at temperatures of 16° C. to 17° C.         -   Root description.—Fine, fibrous; initially white, close to             155C, in color becoming closer to 159C and eventually 164A             with development.         -   Rooting habit.—Freely branching; dense. -   Plant description:     -   -   Plant form and growth habit.—Perennial and evergreen             flowering shrub; compact, upright, outwardly spreading and             globose plant habit; freely branching habit; dense, bushy             and vigorous growth habit; moderate growth rate; freely             flowering habit with numerous showy single flowers.         -   Branching habit.—Freely branching habit with about four to             six basal branches developing on one year old plants;             pinching (removal of terminal apex) will enhance lateral             branch development.         -   Plant height, soil level to top of flowers.—About 35 cm to             50 cm.         -   Plant diameter, area of spread.—About 30 cm to 40 cm.         -   Lateral branch description.—Length: About 5 cm to 20 cm.             Diameter at base: About 2 mm to 5 mm. Internode length:             About 3 mm to 19 mm. Strength: Strong. Aspect: Upright and             outwardly positioned. Texture, developing: Pubescent, fine             greyed orange-colored hairs. Texture, mature: Woody;             pubescent, fine greyed orange-colored hairs. Color,             developing: Close to 145B. Color, semi-hardwood: Close to             145A becoming close to 165A to 165B with development. Color,             mature: Close to 165A.         -   Foliage description.—Arrangement: Alternate; simple. Foliage             retention: Very good winter foliage retention has been             observed on plants of the new Azalea. Length: About 3 cm to             6.5 cm. Width: About 1 cm to 2.5 cm. Shape: Oblanceolate to             elliptic. Apex: Subacute; mucronulate. Base: Cuneate to             attenuate. Margin: Entire; slightly revolute; ciliate.             Venation pattern: Pinnate; reticulate. Texture, upper and             lower surfaces: Pubescent; coriaceous, tough. Color:             Developing leaves, upper surface: Between 137A and 139A.             Developing leaves, lower surface: Close to 138A. Fully             expanded leaves, upper surface: Close to 139A; venation,             close to 138B. Fully expanded leaves, lower surface: Close             to 137C; venation, close to 151A. Petiole: Length: About 6             mm to 10.5 mm. Diameter: About 1 mm to 1.6 mm. Texture,             upper and lower surfaces: Pubescent. Color: Developing             leaves, upper and lower surfaces: Close to N144D. Fully             expanded leaves, upper surface: Close to 138B. Fully             expanded leaves, upper surface: Close to 151A. -   Flower description:     -   -   Natural flowering season.—Spring, April to May, and then             re-flowering during the summer and autumn, July to October,             until frost in South Carolina.         -   Flower arrangement and appearance.—Single star-shaped             flowers arranged in clusters at terminals and sub-terminals             with usually about one to three flower buds and three to six             flowers per cluster; uniform and freely flowering habit;             flowers face upward or outward.         -   Flower appearance.—Flowers rotate and rose-like; single             flower form; flowers with a single whorl of five petals.         -   Flower longevity.—Durable and long-lasting; flowers last             about five to ten days on the plant and about three to five             days as a cut flower; flowers not persistent.         -   Fragrance.—None detected.         -   Flower diameter.—About 7 cm to 8 cm.         -   Flower depth.—About 4 cm to 4.5 cm.         -   Flower bud (before showing color).—Length: About 1 cm to             1.5 cm. Diameter: About 5 mm to 7 mm. Shape: Ovoid. Color:             Close to 137D.         -   Petals.—Arrangement: Single star-shaped flowers have a             single whorl of five petals, fused at the base forming a             wide funnel-shaped corolla. Length: About 3 cm to 3.5 cm.             Width: About 3 cm to 3.5 cm. Shape: Broadly ovate to             orbicular. Apex: Rotund; undulate. Margin: Entire; undulate.             Texture, upper and lower surfaces: Smooth, glabrous;             rugulose; waxy to velvety in appearance. Color: When             opening, upper surface: Close to N81A; spots and speckles,             close to 71A. When opening, lower surface: Close to N81A.             Fully opened, upper surface: Close to N78A; spots and             speckles, close to 71A; color becoming closer to N78B with             development. Fully opened, lower surface: Close to N78A;             color becoming closer to N78B with development.         -   Petaloids.—Quantity: None to rarely one petaloid present.             Length: About 2.5 cm to 3.5 cm. Width: About 1 cm to 1.5 cm.             Shape: Obelliptic to obovate. Apex: Obtuse; may be plaited.             Margin: Entire; undulate. Texture, upper and lower surfaces:             Smooth, glabrous; rugulose; waxy. Color: When opening, upper             and lower surfaces: Close to N81A. Fully opened, upper and             lower surfaces: Close to N78A; color becoming closer to N78B             with development.         -   Sepals.—Arrangement: Five in a single whorl, fused at the             base forming a campanulate to star-shaped corona. Length:             About 1.5 cm to 2 cm. Width: About 3.5 mm to 4 mm. Shape:             Lanceolate. Apex: Subulate. Base: Truncate. Margin: Entire;             slightly revolute; ciliate. Texture, upper and lower             surfaces: Densely pubescent. Color, upper and lower             surfaces: Close to 143C; central blotch and streaks, close             to 60D.         -   Peduncles.—Length: About 2 mm to 4 mm. Diameter: About 3 mm             to 4 mm. Angle: Mostly upright. Strength: Strong. Texture:             Pubescent. Color: Close to 145A; at maturity, close to 164A.         -   Pedicels.—Length: About 1.5 cm to 2 cm. Diameter: About 1.5             mm to 2 mm. Angle: Upright to outwardly. Strength: Strong.             Texture: Pubescent. Color: Close to 60D; towards the base,             close to 145B; becoming closer to N144A with development.         -   Reproductive organs.—Androecium: Quantity of stamens per             flower: About ten. Filament length: About 3.5 cm to 4.5 cm.             Filament color: Close to 67B. Anther shape: Porandrous with             four oblong, tubular to lunate-shaped pollen sacks basifixed             to the filament. Anther length: About 2.5 mm to 3 mm. Anther             color: Close to N186C. Pollen amount: Abundant. Pollen             color: Close to 158B. Gynoecium: Pistil length: About 4.5 cm             to 5 cm. Stigma shape: Round to flattened (capitate). Stigma             color: Close to N79B. Style length: About 4.4 cm to 5.9 cm.             Style color: Close to 61B. Ovary color: Close to 143B.         -   Fruits.—Quantity per plant: About three to five. Length:             About 8 mm to 10 mm. Diameter: About 4 mm to 5 mm. Texture:             Slightly rugulose to scabridulose; glandular, setaceous.             Color: Close to 146C; at maturity, close to 165A.         -   Seeds.—Quantity per fruit: About 50 to 200. Length: About 1             mm to 1.5 mm. Diameter: About 0.2 mm to 0.3 mm. Color: Close             to 165B. -   Weather/temperature tolerance: Plants of the new Azalea have been     observed to be very tolerant to rain and wind. Plants of the new     Azalea have been observed to tolerate temperatures from about     −25° C. to about 40° C. and are suitable for USDA Hardiness Zones 6     to 9. -   Disease/pest resistance: Plants have not been observed to be     resistant to pathogens and pests common to Azaleas. 

1. A new and distinct cultivar of Azalea plant named ‘RLH1-4P19’ as illustrated and described. 